A German prosecutor says he will not follow up a criminal complaint about US Defence Secretary Donald Rumsfeld's role in the Abu Ghraib prison scandal.

Federal prosecutor Kay Nehm said only the US - as the home country of the accused - could pursue any action.

Mr Rumsfeld could have faced arrest in Germany if the case had proceeded.

Mr Rumsfeld's spokesman said shortly afterwards that the defence secretary was "likely" to attend a security summit in Germany over the weekend.

The legal action filed in Germany accused Mr Rumsfeld of war crimes.

The New-York based Center for Constitutional Rights and Berlin's Republican Lawyers' Association said the defence secretary was linked to the abuse of Iraqi detainees at the Abu Ghraib detention centre near Baghdad, which was revealed in photographs.

The complaint was filed in Germany as its laws allow war crimes and human rights violations to be prosecuted across international boundaries.

'Old Europe'

But Mr Nehm said on Thursday that the home country of the accused had primary responsibility for handling any investigation.

The US inquiry has already concluded that Mr Rumsfeld was not directly responsible for the abuse.

The defence secretary admitted last week that the lawsuit was "something that we have to take into consideration" when deciding whether or not he would travel to Munich.

Mr Rumsfeld usually attends the annual conference, which this year begins on Friday.

At the event in 2003 he made headlines by dismissing Germany and France as "Old Europe" for opposing the looming war against Iraq, causing a deterioration in relations with those countries.

The conference this year is expected to focus on hopes for peace in Middle East and the role of the United Nations.